Created a DTO, so the data is decoupled from the command

lib/src/domain/command.rs

@@ -16,9 +16,12 @@
   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
+/// Trait/tag for DTOs
+pub trait Dto {}
+
 /// Trait that all commands must implement.
-pub trait Command {
-    fn execute(&self) -> Result<(), CommandError>;
+pub trait Command<T: Dto> {
+    fn execute(self) -> Result<T, CommandError>;
 }
 
 /// Errors produced by invalid commands

lib/src/domain/project/create.rs

@@ -19,23 +19,19 @@
 use crate::domain::command::Command;
 use crate::domain::command::CommandError;
 
-struct CreateProject {
-    code: String,
-    name: String,
-}
+use super::dto::Project;
 
-impl CreateProject {
-    fn new(code: &str, name: &str) -> Self {
-        Self {
-            code: code.into(),
-            name: name.into(),
-        }
+struct Create(Project);
+
+impl Create {
+    fn new(project: Project) -> Self {
+        Self(project)
     }
 }
 
-impl Command for CreateProject {
-    fn execute(&self) -> Result<(), CommandError> {
-        Ok(())
+impl Command<Project> for Create {
+    fn execute(self) -> Result<Project, CommandError> {
+        Ok(self.0)
     }
 }
 
@@ -45,7 +41,8 @@ mod tests {
 
     #[test]
     fn should_create_project() {
-        let command = CreateProject::new("project", "some project");
+        let project = Project::new("project", "some project");
+        let command = Create::new(project);
         assert!(command.execute().is_ok());
     }
 }

lib/src/domain/project/dto.rs

@@ -0,0 +1,35 @@
+/*
+  TIN - Time tracking application
+  Copyright (C) 2021  Julio Biason
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU Affero General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License
+  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+use crate::domain::command::Dto;
+
+pub struct Project {
+    code: String,
+    name: String,
+}
+
+impl Project {
+    pub fn new(code: &str, name: &str) -> Self {
+        Self {
+            code: code.into(),
+            name: name.into(),
+        }
+    }
+}
+
+impl Dto for Project {}

lib/src/domain/project/mod.rs

@@ -1 +1,2 @@
-pub mod create_project;
+pub mod create;
+pub mod dto;